Silent steel gear



g- 12, 1930- J. R. DUNHAM 1,772,986

S ILENT STEEL GEAR Filed Sept. 13, 1.929

Patented Aug. 12, 1930 barren stares PATENT-creme :rorrn e. DUNHAM, ornew BRUNSWICK, new a ert st r, Assreuon'or one-H LF T JOHN WALDRONoonrosarron, or rraw enunswrox, nnw JERSEY, AcoRroRA- TION or NEW messysrrinn'r srser. GEAR Application filed. September 13, 1929. Serial No.392,440;

which, by slotting of the blank between adjacent teeth, permits theteeth to flex and thus provides a gear which is substantially noiselessin operation.

A still further object of the invention' is to i; provide a constructionof this character permitting the use of spring elements to reinforce theteeth so that the actual metallic support for the teeth provided in theblank maybe reduced to a'point otherwise impossible.

.to These and other objects I attain by the construction shown in theaccompanying drawings wherein, for the purpose of illustration, 1 haveshown a preferred embodiment of my invention and wherein:

Fig. 1 is a side elevation of a gear constructed in accordance with myinvention: and

Fig. 2 is a fragmentary'vertical sectional view therethrough.

Referring now more particularly to the drawings, the numeral 10generally indicates a metallic blank, the periphery of which has beentransversely slotted at 11 to produce gear teeth 12. From the bottoms ofthe slots 11 5 radial slots 13 are extended inwardly into the body ofthe blank, the inner ends of these slots being preferably enlarged asindicated at 14. A convenient method of producing the slots 13and theirenlargements is to transversely bore the blank and then connect eachtransverse bore with the corresponding slot 11 by a saw kerf. Springsare preferably disposed within the slots 13 and more particularly withinthe enlargements 14 thereof.

These springs may constitute any reslient i11- sert in the enlargement14 of the slots, being at present illustrated as coil springs which areplaced in the bores and held in position therein by displacing the metalabout the ends of the bores as indicated at 16,

I In a construction of this-character the enlargements 14 of the slotsproduce weakened .portions 17 permitting: the gear teeth 12 toindependently flexin the line of rotation'of the geain. .The'sp'ringmeans disposed in the illustrated are employed in the bores the constriction of the spring resulting from flexure of the teeth will set upa torsional resistance to flexure while the generally cylindrical formof the spring will provide a novel and BfllGlGIlt support for the wallsof the enlargement of the slot. It will of course be understood that thekerfs and bores producing the slots 13 and their enlargements 14 willfollow the angle of the teeth of the gear.

Since the construction illustrated is capable of a certain range ofchange and modification without departing from the spirit of myinvention, I do not wish to be understood as limiting myself theretoexcept as hereinafter claimed.

I claim:

1. A gear comprising a metallic blank having its periphery slotted toproduce gear teeth and having radial slots extending inwardly from thebase of the teeth forming slots, and a resilient element disposed in theinner end of each slot.

2. A gear comprising a metallic blank having its periphery slotted toproduce gear teeth and having radial slots extending inwardly from thebase of the teeth forming slots, the inner ends of said slots beingenlarged to reduce the metallic web therebetween, and a resilientelement disposed in the enlargement of each slot.

3. A gear comprising a metallic blank having its periphery slotted toproduce gear teeth, there being a bore extending through the blankinwardly of and in alignment with each peripheral slot, a kerfconnecting each bore with the bottom of the associated slot andseparating the metal of the blank between the bore and the slot, and aresilient element disposed in each bore.

4. A gear comprising a metallic blank having its periphery slotted toproduce gear teeth, there being a bore extending through the blankinwardly of and in alignment with each peripheral slot, a kerfconnecting each bore with the bottom of the associated slot andseparating the metal of the blank between the bore and the slot, and acoil spring disposed within and fitting each bore.

5. A gear comprising a metallic blank having its periphery slotted toproduce gear teeth, there being a bore extending through the blankinwardly of and in alignment with each peripheral slot, a kerfconnecting each bore with the bottom of the associated slot andseparating the metal of the blank between the bore and the slot, and acoil spring disposed within and fitting each bore, the metal 7 of theblank at the ends of the bores being displaced to maintain the springsin position.

JOHN R. DUNHAM.

